Do you lube cast bullets?

Big bore PCPs, IMHO, do need some kind of lubrication or the bores need frequent cleaning. Only trying will tell you what your rifle likes.

I do not clean my pellet rifle barrels much as it adversely effects accuracy but the slug guns, 25 and up usually do shoot better with the RIGHT lube and that is the problem. There is not one lube that all guns like!

And then there is the question of wet lube like FP-10 or a 10 wt silicone shock oil or a dry lube that leaves a waxy coat. Wet lube works great but is for the range only... can you imagine trying to use oily bullets in the field hunting? Dry lube might be one of the bicycle chain waxes or something like Rooster Lube (which I use and recommend it works well in several of my air rifles, either straight, diluted 2:1 or 4:1 depending...)

I have a .25 chokeless slug only Marauder that LOVES Pledge spray furniture wax best???

I have used Lyman Quick Slick case lube spray and again, it worked on some bullets in my 45 Texan but not on others! WTF? I sure can't say but that just illustrates how finicky slug lubing can be!

I have even tried powdercoat (not so great) and am waiting on some Hi-tek to be delivered and will try that.